(19)
(11) EP 0 358 351 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
29.01.1992 Bulletin 1992/05

(43) Date of publication A2:
14.03.1990 Bulletin 1990/11

(21) Application number: 89308295.8

(22) Date of filing: 16.08.1989
(51) International Patent Classification (IPC)5: B41L 1/36, C09D 123/08, C09D 191/06
(84) Designated Contracting States:
DE FR GB IT SE

(30) Priority: 29.08.1988 US 237544

(71) Applicant: MINNESOTA MINING AND MANUFACTURING COMPANY
St. Paul, Minnesota 55133-3427 (US)

(72) Inventors:
  • Perrington, Kenneth J. c/o Minnesota Mining and
    P.O. Box 33427 St. Paul Minnesota 55133 (US)
  • DeWanz, James M. c/o Minnesota Mining and
    P.O. Box 33427 St. Paul Minnesota 55133 (US)

(74) Representative: Baillie, Iain Cameron et al
c/o Ladas & Parry 52-54 High Holborn
London WC1V 6RR
London WC1V 6RR (GB)


(56) References cited: : 
   
       


    (54) Edge-bonded sets of carbonless copy paper


    (57) Adhesively edge-padded stack of carbonless copy paper better separates upon fanning into collated sets when a thin layer of hot-melt adhesive is used for the edge-padding. As in the prior art, the outer surfaces of each set should have a release coating such as a fluorocarbon. The layer of hot-melt adhesive includes, by weight:
    20-50% thermoplastic copolymer,
    15-50% tackifying resin, and
    20-60% wax having a melting point of at least 60°C.
    As soon as the adhesive has cooled below its softening point, the stack can be fanned, thus breaking it into sets. Fanning can usually be performed within 45 seconds, because there is no need to wait for the adhesive to dry as has been necessary with the aqueous adhesives that have been used in the prior art. Preferably at least 20% by weight of the adhesive is a paraffin wax that is C₃₅-C₇₀ substantially straight-chain hydrocarbon.







    Search report